Sound-box for phonographs.



C. F. TRUNDY. SUUND 80X FR PHNGRAPHS. APPUCATION HLED ww x2, mm

1,269,659. Paiutm Juno i5, 1918 UNITED sTATEs PATENT oEEIoE.

CHARLES P. TRUNDY, Ogabl, MASSACHUSETTS. a

'i No till 'iw ,drew 'Mir .wn fili Jliwiii i -w ""w wais "d," y4 t," t.' ".lt "'lLi-t" 1,269,659. 'Sveclamflett Batent- Patented June 18;1129184V si i *Dalmatian md .my 12;'1'917 seriailfo: 130,114'. :"if' i 4 1 f "i 1 "en u To all wh0m it may e'once'm.' f l f by the"engagement'o' the-needle with the Be 1t known that I, CHARLES P. TEUNDY, "record l.are thus prevented from being" tr'as- "5'" a Citizen of the United Stat/es, residing at initted to the `tone `arm sleeve, and theee'to""' Boston,1n the eonntyfof Suffolk and State of the tone arm, and are therefore suppressedr't Massachusetts, have invented eertamnew or destroyed? The tone arm sleeve'is'seenred` @i and useful Improvementsi in Sound-Boxesv to the sound-box by' means' of screws 9,A two*- tor Phonographs; and Iv do hereby declarel 4 of such screws being used', onea'bove and the the following to be 'afnllf clear-and exactl 'other below the center' ofy the -sound box. #"*Aif deseriptlon ofthe i11vention,` such as will enf1 4The screws 9 pass through lthe bottomof' the` mi able others skllledin the art `to which t;-a};i-4 sound box,` "through the rubber diskfS, andi 'f' al t pertains to make and use the same. are screwed into the tone term sleeve. Under The present invention relates to an iinthe heads-*of the kseriewsfare `provided metal "fr proven'ient in sound boxes for phonographswashers in the first place,which'eolne in con'- The object of the present invention is to tact with `the heads of the 'screwsl whieh'q reorganize and improve theConstruction of metal washers take against the rnbberivaslv -rz .2, sound boxes for phonograpbs in general and ers,l whit-lr in turn rest on the bottom ofithewo espeeially in the direction of preventing unscrew head eavities'in the sound box.'v It is i'` desirable vibrations from being transmitted rcommon inthis art to interpose axrelastie from the. needle to the. tone arni. -T o the `.ring betweerrthe sound box andthe tone ariir -745 above ends .thepresent invention consists. of forthe pui-posent' d-issipatingtthe,ribrationse r t. 1 the sound box hereinafter .described a ndaparroinnninieated to'the sound box by' the diai .i i. tienlarly defined in the .elaiuis phragnt and thusreduce tO-a miniminruthe In the accompanying-drawingsf.illustrate Etramsrnission of such vibrations to tthetone 1; ing the preferred form of` the iliveiti(inFig' arm. In ,these prior devices, however, the` 80 ure l is a front elevation of the sound box;f connection .betweeniithe -sound box amdI the; ,it es. Fig. Q is a sectional elevation, taken ataright, vtone arm has been such that' pressure on; the t angles to Fig. l; Fig. 'isa plan vimvof the' interposed elastic ring or diskA iszuniferm rubber disk, and Fig. 4 is an elevation ofthe throughout the annular point of ieontaetp 1. same. and` in View of this fart. and the further fact $5i The sound box 1 is provider] with a dia,- that ity is.,imperati\'e that the sound box shall s .gr phraglu 2. needle arm 3. andthe like, which,l be L'onnertzed firmly yto the tone. arm, yit is f exeept as hereinafter pointed out, aref'of any `impossible to keep the vrdn-ations of `the y, usual or preferred eonstrurtion. .The needle sound box from being tlaIlSlllled .111.5 ltllgc arm is pivoted upon the, phot screws [Lwhieb` measure to the tone arul. i Anlideal Condr- QQ are supported in ilre ears 5, projecting frour tion would prolnrbly. exist 4 were it. possible to n; the sides of the soundbox.. These pivot. have the eonstrlvIe-tion suoli that allthe vibra* screws are secured in'plaee b'x/set .ssrreivsltbl tions would lie-taken up in `the sound box *mi so that when ther-are adjusted to eorrert structure., but this isimpossiblejn l\"1e,\-.V.of\s position they maybe seeured in placeaud altrui-the neeossity for a, foirlyhlirm A.eonneetion bessen not.- liable to be loosened by heavy vibratiom tivee'n the `sound ,box and; the tonepalgm. `I i .The beads ol' the set-screws t'are` reeeived in Vhave' discovered-a way, ofapproaehing lll/11S i.

depressions or eavities Vin,.lillssese pro-jecting.:V ideal construction bywprovidalng means I from tbe sides offthe ears-5 so that tlierxualre whereby the, vibrations oftthe soupd-boxyarlfewbv, not. liable lo engr-age any objeetbrilb whii'lr` t-lissipatedIlnost ent i.re.l vwhileatthgsaure1go they might rome in eontart` korto be dis aimery provdinga emmeetiolrbetween. e turbed b v the user because the \Y are so von# :sound yboxanrd the tone arm wl 1icl1v\rl5l-. e eealed and ineonspieuous. Atl ,tbuuear-of amply rigid,. 1 @ne preferred wayi of, doing the sound box i there is a depressionor*eau this. isop@ provide (he, elastic. wmgpi at a. ity whit-b is eyliudriral inforum-.told.freeeives, point where penetrated `by eaqhiozf the the; sound boxend of the tone arnrsieeve 7. Between, the sound box and tbe tone. arln sleeve, isreeeived the mlfbber-disk ttrn'hirh is that by` the empbngnient otivo.serexvsyandump y two thickened portapu.arrnarged at djarnetrisjbw interposerbbelween4 the tone box :und I hetene eallvfopposite porntsshowlgfthe Usgin .t arin sleeve, for tbe purposabt',preventing the .Ylioxis 'fastened hrrn'ly t-odhg toner44 En" transmission of vibration from theametotbo.- :these diametrieally-opposlte points, w trier-.jpg j other. Vibrations; set up in the sound pointsy betweenfthe sc leivillrl wryu'litteg` fifi serews withy the thielgenegl. portitnvljl,` SQ, t :es

pressure on the body of the ring thus providing one or two or more har clamping` points around the vibration-dendening ring and reducing the pressure to a minimum on the ring at lntermediatepoints insures the vibrations of the sound box being in a large measure dissipated by being taken up or destroyed in the lightly-clamped parts of the ring1 In the above-described construction, there is believed to be a slight oscillation of the sound box parallel with the axis of the needle; this construction is therefore particularly adapted for use in connection with sound records in which the sound grooves are cut by a laterally vibrating recording stylus. In this case, the plane of the diaphragm of the reproducing sound box is placed parallel with the series of sound grooves, and it has been found empiricall that the best vresults are obtained if the axis of oscillation of the sound box is parallel with the axis of the needle, although good results are obtained in eliminating undesirable vibrations in the tone arm where the axis of oscillation of the sound box is at ri ht angles to the axis of the needle. But were sound records are used in which the sound grooves are cut by a vertically vibrating recording stylus, .that is to say, on the hill-and-dale principle, the plane' of the,` diaphragm of the reproducing sound box is transversely placed to the series of sound groovesso as to permit the lower end of the reproducing needle to rise and fall with the undulations of the sound grooves. It is apparent that in this latter case the axis of oscillation of the sound box must be parallel with the pivotal axis of the needle, otherwise, the sound box would not oscillateto take up the undesirable vibrations. But whether the sound grooves of the sound records are cut on the lateral `principle oron the vertical principle, the present invention eliminates the undesirable vibrations in the tone arm by connecting the sound box with the tone arm sleeve in such manner that the sound box will be permitted to yieldingly oscillate with respect to the tone arm sleeve, thereby eliminating the communication of vibrations from the sound box itself to the tone arm. In the accompanying drawing the sound box is shown as oscillating on a vertical axis. It will be understood, however, that the invention is not limited to a sound box so mounted, but includes within its .sxope a` sound box mounted to oscillate with respect to the tone ann sleeve, whatever the position of the axis of oscillation. i

The feature hereinbefore referred to of pivoting the needle arm on the axis intersecting the axis of the needle arm is a useful feature of the invention which contributes measurably to its successful operation,

to a minimum.

although other features of the invention may be used without it, if desired. Another feature which is of importance in this construction resides in that by virtue of which the rubber which connects the tone arm to the sound box is entirely covered by an annular projection from the tone arm sleeve into the exposed to the sound waves is of advantage i in roducing a box of superior construction, an for more accurate reproduction of the sound waves from the record.

It will be observed that the screws 9 are inserted from the inside of the sound box, so that their heads will be inclosed and hidden by the diaphragm 2. Arranging the screws in this manner not only provides a neat and smooth and practically invisible connection with the tone arm, but also renders it impossible for the adjustment to be disturbed without first taking out the diaphragm, whereby the likelihood of the ad- ]ust'ment being disturbed after it is properly adjusted in the factory will be reduced With this construction, it will'be seen that the ends of the screws may be terminated in the body of the tone arm, so that the surface of the tone arm may be entirel free from projections.

Having thus described the invention, what is claimed is:

1. A sound box for phonographs, having, in combination, a box having a bottom, a tone arm sleeve having a portion adapted to fit the bottom of the box, a rubber washer interposed between the tone arm sleeve and4 the sound box, and conmaetionsl between the tone arm sleeve and the sound box, provision being made to positively insure a harder clamping action on the Washer, at two'diametrlcally-opposite points than at the interifnedilate points thereof, for the purpose set ort '2; A sound box for. phonographs, having, in combination, a box, a tone arm sleeve, a washer havingr diametrically opposed thickened portions, and means vfor holding the tone arm on the sound box.

3. A sound box for phonographs, having, in combination, a sound box, a tone Varm sleeve, a rubber diskhaving two diametrically opposed thickened portions, and fastening means passing 'through said thickened portions for, holding the tone arm sleeve to the sound box, causing greater pressure to be exerted upon the thickened portions of the rubber disk.:

4. A sound box for phonographs,y having, in combination, a box, a tone arm sleeve, a 'ashnr inturposed bciwecn the sleevv and box for holding the tone arln sleeve and box together, said ione arln sleeve and box having provisions tol cover the rubber disk betwoen thv two` and said washer having pr0- vision for positivoly insuring a harder damping action on the washer at two dia- 10 metricaILV-opposite points than at the intermediato points of ihn Pusher, for the purpose Set forth.

In combination with H10 huh of a tonearm.` a sound-box, fasivning screws inserted through the wail of tinnonndvhox and hav* ingr their threaded @mis terminating in Said huh. a diaphragm niolmtrd in tho sonudhon so as to A@over the sm'mv-lwada, and a. macdle-hohicr Inonnlvd on the sound-box.

CHARLES P. TRUNDY. 

